There are numerous manufacturers and sellers of level sensing devices, each employing simple to very complex methods of sensing the presence of material at the point of contact or within the monitoring area. Most of the devices are designed for specific applications and therefore operate most reliably when situated within the environment for which they are designed. For example, a system for sensing the level of powder material within a container may not be suitable for sensing the level of a liquid and vice versa.
In a typical prior art level sensing system employing a drop weight, which is positioned in a standby or home position above the material between measurement cycles, the drop weight tends to creep towards the top surface of the material being sensed, such that over time the home or standby position of the drop weight departs substantially away from its original position. When the container is then refilled with the material, the drop weight would typically become buried in the material. Under this situation, when the system tries to lift the weight during a measurement cycle, the cable supporting the drop weight would typically break or the system would stall, which could lead to premature failure of the cable and unnecessary down-time to fix the problem.
These devices typically employ high technology and sophisticated components that support the associated sensing mechanisms and circuity, thereby requiring relatively sophisticated maintenance personnel to maintain, trouble-shoot, calibrate and adjust the devices.
There is therefore a need for a material sensing system that addresses the problems of prior art devices.